Add parallel convert

cmd/go-qcow2reader-example/convert.go

@@ -0,0 +1,88 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/lima-vm/go-qcow2reader"
+	"github.com/lima-vm/go-qcow2reader/convert"
+	"github.com/lima-vm/go-qcow2reader/log"
+)
+
+func cmdConvert(args []string) error {
+	var (
+		// Required
+		source, target string
+
+		// Options
+		debug   bool
+		options convert.Options
+	)
+
+	fs := flag.NewFlagSet("convert", flag.ExitOnError)
+	fs.Usage = func() {
+		fmt.Fprintf(flag.CommandLine.Output(), "Usage: %s convert [OPTIONS...] SOURCE TARGET\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+	fs.BoolVar(&debug, "debug", false, "enable printing debug messages")
+	fs.Int64Var(&options.SegmentSize, "segment-size", convert.SegmentSize, "worker segment size in bytes")
+	fs.IntVar(&options.BufferSize, "buffer-size", convert.BufferSize, "buffer size in bytes")
+	fs.IntVar(&options.Workers, "workers", convert.Workers, "number of workers")
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+
+	if debug {
+		log.SetDebugFunc(logDebug)
+	}
+
+	switch len(fs.Args()) {
+	case 0:
+		return errors.New("no file was specified")
+	case 1:
+		return errors.New("target file is required")
+	case 2:
+		source = fs.Arg(0)
+		target = fs.Arg(1)
+	default:
+		return errors.New("too many files were specified")
+	}
+
+	f, err := os.Open(source)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	img, err := qcow2reader.Open(f)
+	if err != nil {
+		return err
+	}
+	defer img.Close()
+
+	t, err := os.Create(target)
+	if err != nil {
+		return err
+	}
+	defer t.Close()
+
+	if err := t.Truncate(img.Size()); err != nil {
+		return err
+	}
+
+	c, err := convert.New(options)
+	if err != nil {
+		return err
+	}
+	if err := c.Convert(t, img, img.Size()); err != nil {
+		return err
+	}
+
+	if err := t.Sync(); err != nil {
+		return err
+	}
+
+	return t.Close()
+}

cmd/go-qcow2reader-example/info.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/lima-vm/go-qcow2reader"
+	"github.com/lima-vm/go-qcow2reader/image"
+)
+
+func cmdInfo(args []string) error {
+	var (
+		// Required
+		filename string
+
+		// Options
+		debug bool
+	)
+
+	fs := flag.NewFlagSet("info", flag.ExitOnError)
+	fs.Usage = func() {
+		fmt.Fprintf(fs.Output(), "Usage: %s info [OPTIONS...] FILE\n", os.Args[0])
+		fs.PrintDefaults()
+	}
+	fs.BoolVar(&debug, "debug", false, "enable printing debug messages")
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+
+	switch len(fs.Args()) {
+	case 0:
+		return errors.New("no file was specified")
+	case 1:
+		filename = fs.Arg(0)
+	default:
+		return errors.New("too many files specified")
+	}
+
+	f, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	img, err := qcow2reader.Open(f)
+	if err != nil {
+		return err
+	}
+	defer img.Close()
+
+	imgInfo := image.NewImageInfo(img)
+	j, err := json.MarshalIndent(imgInfo, "", "    ")
+	if err != nil {
+		return err
+	}
+	if _, err = fmt.Println(string(j)); err != nil {
+		return err
+	}
+	if err = img.Readable(); err != nil {
+		logWarn(err.Error())
+	}
+
+	return nil
+}

cmd/go-qcow2reader-example/main.go

@@ -1,25 +1,20 @@
 package main
 
 import (
-	"encoding/json"
-	"errors"
-	"flag"
 	"fmt"
 	"io"
 	"os"
 
 	"github.com/klauspost/compress/zstd"
-	"github.com/lima-vm/go-qcow2reader"
-	"github.com/lima-vm/go-qcow2reader/image"
 	"github.com/lima-vm/go-qcow2reader/image/qcow2"
 	"github.com/lima-vm/go-qcow2reader/log"
 )
 
-func warn(s string) {
+func logWarn(s string) {
 	fmt.Fprintln(os.Stderr, "WARNING: "+s)
 }
 
-func debugPrint(s string) {
+func logDebug(s string) {
 	fmt.Fprintln(os.Stderr, "DEBUG: "+s)
 }
 
@@ -40,82 +35,48 @@ func newZstdDecompressor(r io.Reader) (io.ReadCloser, error) {
 	return &zstdDecompressor{dec}, nil
 }
 
+func usage() {
+	usage := `Usage: %s COMMAND [OPTIONS...]
+
+Available commands:
+  info		show image information
+  read		read image data and print to stdout
+  convert      convert image to raw format
+`
+	fmt.Fprintf(os.Stderr, usage, os.Args[0])
+	os.Exit(1)
+}
+
 func main() {
-	log.SetWarnFunc(warn)
+	log.SetWarnFunc(logWarn)
 
 	// zlib (deflate) decompressor is registered by default, but zstd is not.
 	qcow2.SetDecompressor(qcow2.CompressionTypeZstd, newZstdDecompressor)
 
-	if err := xmain(); err != nil {
-		fmt.Fprintln(os.Stderr, "ERROR: "+err.Error())
-		os.Exit(1)
-	}
-}
+	var err error
 
-func xmain() error {
-	flag.Usage = func() {
-		fmt.Fprintf(flag.CommandLine.Output(), "Usage: %s [OPTIONS...] FILE\n", os.Args[0])
-		flag.PrintDefaults()
+	var cmd string
+	if len(os.Args) > 1 {
+		cmd = os.Args[1]
 	}
-	var (
-		debug      bool
-		info       bool
-		bufferSize int
-		offset     int64
-		length     int64
-	)
-	flag.BoolVar(&debug, "debug", false, "enable printing debug messages")
-	flag.BoolVar(&info, "info", false, "print the image info and exit")
-	flag.IntVar(&bufferSize, "buffer", 65536, "buffer size")
-	flag.Int64Var(&offset, "offset", 0, "offset to read")
-	flag.Int64Var(&length, "length", -1, "length to read")
-	flag.Parse()
-	if debug {
-		log.SetDebugFunc(debugPrint)
+	var args []string
+	if len(os.Args) > 2 {
+		args = os.Args[2:]
 	}
 
-	args := flag.Args()
-	switch len(args) {
-	case 0:
-		return errors.New("no file was specified")
-	case 1:
-		// NOP
+	switch cmd {
+	case "info":
+		err = cmdInfo(args)
+	case "read":
+		err = cmdRead(args)
+	case "convert":
+		err = cmdConvert(args)
 	default:
-		return errors.New("too many files were specified")
-	}
-	fName := args[0]
-
-	f, err := os.Open(fName)
-	if err != nil {
-		return err
+		usage()
 	}
-	defer f.Close()
 
-	img, err := qcow2reader.Open(f)
 	if err != nil {
-		return err
-	}
-
-	if info {
-		imgInfo := image.NewImageInfo(img)
-		j, err := json.MarshalIndent(imgInfo, "", "    ")
-		if err != nil {
-			return err
-		}
-		if _, err = fmt.Println(string(j)); err != nil {
-			return err
-		}
-		if err = img.Readable(); err != nil {
-			warn(err.Error())
-		}
-		return nil
-	}
-
-	if length < 0 {
-		length = img.Size()
+		fmt.Fprintln(os.Stderr, "ERROR: "+err.Error())
+		os.Exit(1)
 	}
-	buf := make([]byte, bufferSize)
-	sr := io.NewSectionReader(img, offset, length)
-	_, err = io.CopyBuffer(os.Stdout, sr, buf)
-	return err
 }

cmd/go-qcow2reader-example/read.go

@@ -0,0 +1,73 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+
+	"github.com/lima-vm/go-qcow2reader"
+	"github.com/lima-vm/go-qcow2reader/log"
+)
+
+func cmdRead(args []string) error {
+	var (
+		// Required
+		filename string
+
+		// Options
+		debug      bool
+		bufferSize int
+		offset     int64
+		length     int64
+	)
+
+	fs := flag.NewFlagSet("read", flag.ExitOnError)
+	fs.Usage = func() {
+		fmt.Fprintf(fs.Output(), "Usage: %s read [OPTIONS...] FILE\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+	fs.BoolVar(&debug, "debug", false, "enable printing debug messages")
+	fs.IntVar(&bufferSize, "buffer-size", 65536, "buffer size")
+	fs.Int64Var(&offset, "offset", 0, "offset to read")
+	fs.Int64Var(&length, "length", -1, "length to read")
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+
+	if debug {
+		log.SetDebugFunc(logDebug)
+	}
+
+	switch len(fs.Args()) {
+	case 0:
+		return errors.New("no file was specified")
+	case 1:
+		filename = fs.Arg(0)
+	default:
+		return errors.New("too many files were specified")
+	}
+
+	f, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	img, err := qcow2reader.Open(f)
+	if err != nil {
+		return err
+	}
+	defer img.Close()
+
+	if length < 0 {
+		length = img.Size()
+	}
+
+	buf := make([]byte, bufferSize)
+	sr := io.NewSectionReader(img, offset, length)
+	_, err = io.CopyBuffer(os.Stdout, sr, buf)
+
+	return err
+}